Machine for tamping earth



Feb., 25, E936. J. EGGERT MACHINE FOR TAMPING EARTH Filled July 5, 19322 sheets-sheet .1

1N VEN TOR Josep/7 @gef/f A TTORNE YS.

Feb. 25, 1936. 1 EGGERT LQS MACHINE FOR TAMPING EARTH Filed July 5, 19522 Shee'tS-Sheet 2 Patented Feb. 2,5, 1936 PATENT OFFICE MACHINE FORTAMPING EARTH Joseph Eggert, Columbus, Ohio; Emma L. Keny admmistratrixof said Joseph Eggert, deceased Application July 5, 1932, Serial No.620,806

18 Claims.

My invention relates to a machine for tamping earth. It has to doparticularly with a machine for tamping earth under a side form such asis commonly used in the construction of concrete highways, although itis not necessarily limited to use in this field of operation.

In the prior art, other tamping machines have been devised but, in manycases, these tamping machines are of a cumbersome nature andconsiderable difficulty is involved in the operation of such apparatusesand in the placing of them in position for operation. Some of theseother tamping machines are used in the tamping of dirt under railroadties, wherein the required conditions of operation are considerablydifferent.

One of the objects of my invention is to provide a. tamping machine ofthe type indicated which is so constructed that it can be placed upon aconcrete sideform or removed therefrom with facility by one man.

Another object of my invention is to provide a machine of the type inquestion which may be moved along the side form automatically during itsoperation but which may also be moved along the side form eitherforwardly or rearwardly like a wheel-barrow without danger of accidentaldisplacement from the side form.

Another` object of this invention is to provide a transporting wheelwhich is normally maintained in inoperative position during the tampingoperation but which is so disposed that it can be rendered effective forsupporting the device in its travel along the form with a minimum ofdifficulty.

Another object of my invention is to provide a simple and effectivemeans for oiling the side form for the purpose of preventing thesticking of the concrete thereto.

My invention preferably embodies a carriage provided with a pair offlanged traction rollers which are designed to travel along the top ofthe side form and to prevent accidental displacement therefrom. Thesetraction rollers are preferably driven by an internal combustion engineand are effective to propel the carriage along the concrete form withoutmanual assistance. The device further preferably embodies a tampingmember on each side of the concrete form and these tamping membersreciprocate in downwardly converging paths, this reciprocation beingeffected by a driving connection from the internal combustion engine,

My device further comprises a transporting wheel which is adjustable todiierent positions and which is designed to roll idly along the top ofthe concrete form during the tamping operation In this position, thetransporting roller may be made immediately effective by lifting therear end of the machine through the medium ,of

a handle structure provided for this purpose. In one position ofadjustment, the transporting roller is designed to ride upon the ground,so that the machine may be moved from place to place like awheel-barrow.

My apparatus also comprises an oil tank with a delivery conduit leadingtherefrom. In conjunction with this, I have provided a conduit leadingfrom the exhaust of the engine and the oil conduit hasits outletdisposed within the conduit which leads from the exhaust so that theexhaust gases pick up the oil and carry it in vapor form. These exhaustgases are then delivered to the concrete form so that the oil carriedthereby is deposited on the form. 1,5

There are various other features of my invention. These features will beexplained more in detail as this description progresses.

The preferred embodiment of my invention is shown in the accompanyingdrawings wherein similar characters of reference designate correspondingparts and wherein:

Figure 1 is a perspective view of a concrete form with my machinemounted thereon.

Figure 2 is a rear elevation of my machine 25 mounted on the concreteform, many of the parts being removed so as to more clearly show thearrangement of the tamping units and the driving mechanism therefor aswell as the manner in which the oil-laden exhaust gases are applied to30.

the form.

Figure 3 is a detail, in side elevation, of the front end of myapparatus showing the transporting wheel in two of its positions ofadjustment.

Figure 4 is a plan view of the structure shown in Figure 3.

Figure 5 is a more or less diagrammatic View of my apparatus in theposition of the parts when the apparatus is being transported with thetransporting wheel on the ground.

Figure 6 is a diagrammatic side elevation of my apparatus showing how itis initially positioned on the side form so that the transporting wheelcan be adjusted to the desired position.

Figure 7 is a diagrammatic side elevation of my apparatus with the partsshown in the position which they assume during the tamping operation.

Figure 8 is a diagrammatic side elevation of my apparatus with the partsin the position which they assume when the apparatus is beingtransported along the side form.

In the drawings, a concrete side form is shown at A. It may take variousforms but, as shown, it is provided with a horizontal base plate havinga narrow upstanding iiange on one edge and a wide upstanding flange onthe other edge. This wide upstanding flange is inwardly and thendownwardly bent in the usual form of rail construction, as illustratedin Figure 2.

My apparatus preferably comprises a carriage which may be generallydesignated I and which is provided with vertically extending flanges 2and 3 which serve as bearings for the support of shafts 4 and 5, one ateither end of the carriage. These shafts are preferably mounted forvertical adjustment on the carriage by means of bearing members 5 and l,this vertical adjustment being effected through the medium of boltswhich may be placed in any one of the series of bolt holes 8 and 9. Thisstructure facilitates the proper location of the tamping units, to bedescribed, regardless of the height of the concrete side form upon whichmy apparatus is operating. VThe manner in which this is effected will bemore apparent with the further description of this machine.

Keyed to the shafts 4 and 5 are flanged rollers respectively designatedI0 and II. Each roller embodies two spaced annular flanges and the depthof the flanges is such that they will serve to prevent lateraldisplacement of the front end of the machine from the top of the sideform, even when this machine is being manually propelled or pulled alongand upon the side form with the major portion of its weight supported bythe transporting wheel riding upon the side form.

Secured to the sides of the flanged rollers are sprockets I2 and I3, sothat the rotation of one shaft and the roller carried thereby will beeffective to rotate the other shaft and the roller carried therebythrough the medium of a sprocket chain I4. The shaft 5 is provided atone end with a large sprocket gear I5 which is driven from a smallsprocket I 6 through the medium of a sprocket chain I'I. The smallsprocket I6 is keyed upon a shaft I8 to which is also keyed a largesprocket gear i9 which is driven by a sprocket chain 2G from a sprocketgear (not shown) carried upon a transverse shaft 2|. 'Ihe transverseshaft 2| is driven in any suitable manner from the internal combustionengine 22'.

-As illustrated best in Figure 2, the shaft 2| extends between thevertically disposed channel members 22 and 23 which are supported by thebody portion of the carriage in any suitable manner. This shaftprojects, at both ends, bevond the outer sides of the channel members 22and 23 and has disks 24 and 25 keyed thereon.

l Eccentrically mounted on these disks are crank pins 25 and 2l to whichare connected reciprocating means for actuating the tamper units. Sincethese tamper units and their operating mechanisms are identical, thedescriptionv of one will f suflice'.

As shown in Figure l, the crank pin 21 fits rotatably within a knuckle28 and this knuckle 28 is provided with a bore extending at right anglesto the crank pin, so that it may readily align with the perforated ears29 and 30 of a fork member 3|. A pin 32 extends through these aligningopenings to produce a universal joint structure for the connection ofthe upper end of a pitman rod construction to the crank pin 2'I.

The pitman rod construction further comprises a bolt 33 which extendsupwardly through the base of the fork 3| and has a rectangular head 34disposed within said fork. The lower end of this bolt extends throughthe base of an inverted fork 35 and is likewise provided with arectangular head 35. The fork 3| and the fork 35 are each provided withcollars 3'I and 38 respectively which may be formed integrally thereonand which are embraced by the extremities of a coil spring 39 which alsosurrounds the bolt 33.

The legs of the fork member 35 are pivotally connected to a sleeve 40 ofa universal joint connection similar to'that which connects the upperend of the pitman rod to the crank pin 26. This universal jointconnection is effective to connect the lower end of the pitman rod to anupstanding lug 4| of a lever 42 which is fulcrumed as at 43 and whichhas its outer end pivoted as at 44 to a tamping unit 45. The tampingunit 45 is maintained in converging relation to the base of the sideform A by means of a guide member 46 within which it is reciprocable.

It will be seen from this that the tamping unit is mounted forreciprocation towards and from the dirt beneath the edge of the sideform and at such an angle as to adequately pack the dirt under this sideform. The yielding pitman structure is such that it will compensate forshocks and jars which inevitably occur in varying degrees depending uponthe particular substance being operated upon. The universal connectionsfurther compensate for irregular resistance to the tamping blows. Withthe tamping units on both sides of the device, they effect a balancingaction which, together with other structural features of the device,enable my apparatus to travel automatically along the side form andeffect a tamping operation during travel in a highly satisfactory mannerwithout danger of accidental displacement from the form.

In order to preclude the sticking of the concrete or any portion thereofto the side form, it is desirable to apply oil thereto. I have provideda simple and highly effective means for automatically applying oil tothe side form as the tamping operation progresses.

The means for effecting this oiling operation preferably comprises asource of oil supply in the form Of a tank 4'I which is carried upon mycarriage, preferably in a comparatively elevated position. This tank 4'Iis provided with outlets in its bottom, preferably adjacent either endthereof and leading into conduits 48 and 49 which are respectivelyprovided with controlling valves 50 and 5I. These conduits 48 and 49extend downwardly into converging relation with opposite sides of theupstanding wall of the side form and are open at their lower ends. It isdesirable that they be, approximately, quarter inch pipes with theirlower ends open.

The lower ends of these pipes extend into elbow nozzles 52 and 53(Figure 1) and may be concentrically disposed within such nozzles. Theypreferably terminate a short distance within the nozzle outlet.

The elbow nozzles 52 and 53 are mounted upon conduits 54 and 55 which,through the medium of flexible conduits 56 and 51, receive the exhaustgases from the internal combustion engine 22'. The result of thisstructure is that, when the internal combustion engine is operating andthe valves 5!) and 5| of the oil conduit are open, the oil flo-Ws bygravity through the conduits 48 and 49 to the outlets thereof and aremet at this point by the exhaust gases of the internal combustionengine, These gases vaporize and pick up this oil in the elbow nozzlesand deliver these oil-laden gases onto th'e side form. The result ofthis action is to deliver the oil in vaporized form and more or lessunder pressure onto both sides and the top of the side form, as will beapparent from the showing of Figure 2. Furthermore, the heat from theexhaust gases thins the oil so that it more readily vaporizes. Thispressure application insures application of the oil over a substantialarea of the side form. Thus, all of the surface area of the side formswith which the concrete is liable to contact andv to which it mightotherwise adhere is fully oiledv to preclude such adherence.

My apparatus is further provided with meansv whereby it may betransported either upon the ground or upon the side form like awheel-barrow. Thus, at its rear, there is provided a bifurcated handle60 which is preferably horizontally disposed but which is provided atits innermost end with a downwardly inclined portion 6I that flts in asocket member 62 rigidly mounted upon the carriage structure. The socketmember 62 is split on one side and a handle 62 is provided so that thesocket member 62 may be caused to grip the handle 60 or may be adjustedto permit the handle 66 to swing in the socket. The handle 60 may beswung in its socket from a substantially horizontal position, as shownby full lines in Figure 1, to a substantially vertical position as shownby the dotted lines. This adjustment of the handle 60 is for a purposewhich will be hereinafter apparent. The handle 62 may operate anysuitable means (not shown) for causing the socket member 62 to grip thehandle 60 or to allow it to freely swing therein.

At its forward end, the carriage is provided with a transporting wheel63 that is journaled upon a transversely extending portion 64 of aU-shaped member 65. The U-shaped member 65 has a transversely extendingportion 66 at its rear, as shown in Figure 4, and this portion 66 ispvotally disposed in parallel plates 61 and 68, which plates projectforwardly from the front end of my carriage structure.

Intermediate the parallel plates 61 and 68, the transverse portion 66carries a collar 69 which is preferably secured thereto by a set screwVand disposed adjacent the inner surface of the member 61. Thistransverse portion 66 also carries a compression spring 16 insurrounding relation thereto and lying between the inner surface of theplate 68 and the collar 69. The portion 66 is of such a length that itwill be capable of a substantial axial movement within its bearings andits outermost extremity is provided with a pin 'H to limit axialmovement in one direction.

The forward end of the plate 68 is provided with a keeper member 'l2 inthe form of a laterally extending flange whose outer edge is downwardlyand outwardly inclined (Figure A1). This keeper-member is of such formand so located that it will cooperate with the U-shaped member 65 topermit movement of the forward end of said U-shaped member downwardly toplace the transporting wheel 63 on the ground. During this downwardmovement, as for example from the position shown in Figure 1 to theposition shown in Figure 3, the portion 66 of the U-shaped member willmove axially against the pressure of the coil spring l', as indicated inFigure 4, until the U-shaped member 65 passes below the point of thekeeper-member 12. At this time, the compression spring 'iG willreverse-the axial movement of the portion 66 and cause the latching ofthe U-shaped member 65 below the keeper 12.

The collar 69 which is carried by the portion 66 of the U-shaped member65 is further provided with an integral upstanding extension 13 which ismore or less Lshaped and which is provided at its extremity, as shown inFigure 3, with an adjustable set screw M Inspection of Figure 3 andFigures 5, 6 and '7 will show that this member 'I3 assumes severaldifferent positions during the 1 ation.

adjustment of the transporting wheel 63 to theseveral positions which itmay occupy, as will be explained during the description of the operationof my device.

My apparatus is further provided, as shown in Figures 2, 3V and' 4 witha depending: pin 16 which is supported from the bed plate ofv thecarriage of my machine by nuts 16. This pin is particularly useful inthe placing of my transporting wheelon the side form in the positionshown in Figure 1, being used to temporarily support the forward end ofthe machine upon the side form so as to relieve the U-shaped member 65and the transporting wheel 63 from the weight of any portion of themachine during its adjustment from the fullv line position of Figure 3Vto the dotted line position thereof, as will more clearly appear fromthe description of the operation.

In operation, my apparatus may be transported to the side form uponwhich it is to be mounted as shown in Figure 5, wherein the majorportion of the weight of the machine is carried by the transportingwheel 63 and the device is trundled like a wheel-barrow. Inl placing thedevice upon the side form, the supporting wheel 63 is positionedimmediately adjacent the side of the side form and the rear roller Il isso positioned that its flanges embrace the top of the form. Then theforward end of the machine is swung into such position that the lowerend of the pin 15 rests upon the top of the side form and inwardly alongthe inclined edge of the machine thereon.

In this position, the transporting wheel 63 is relieved of all weight ofthe machine and the operator may then grasp the U-shaped member 65 andmove it to the dotted line lposition of Figure 4. This transportingwheel may then be lifted and moved to the position shown in Figure '7,these lifting and lateral movements being facilitated by the action ofthe spring 10 which tends to cause the member 65 to ride upwardly andinwardly along the inclined edge of the keeper 12`.

In this position of the transporting wheel, the front end of the machinemay be readily moved laterally to complete the movement of the pin 15across the top of the side form and into the position in which it isshown in Figure 2. This movement permits the front roller l0 of themachine to drop down so that its flanges embrace the top of the sideform. Then, the apparatus will be in the position shown in Figure '1, inwhich position the transporting wheel 63 may ride idly upon the top ofthe side form. When the machine is so positioned on the side form thehandle 60 is swung to a substantially vertical position, as shown by thedotted lines in Figures 1 and 7, and is secured in such position byoperation of handle 62.

By starting the internal combustion engine by the pedal lever shown inFigure 1 or by any other suitable apparatus and by manipulating theclutch mechanism (not sho-wn), the rollers l0 and Il will be positivelydriven and the tamper mechanism will be set in operation. The device isso balanced that it will ride securely upon the side form and will bepropelled along the same by means of the rollers while the tampingmechanism simultaneously performs the tamping oper- Furthermore, theoperator may Walk directly behind the machine and keep it in balancedposition on the form by means of the vertically extending handle 60.Either one or both of the valves 50 and 5I may be open and this willresult in the automatic application of the oil-laden exhaust gases tothe side form.

During the operation of a machine of this type, it is frequentlynecessary or desirable to transport the machine rearwardly or forwardlyalong the side form while the tamping mechanism and the oiling mechanismis inoperative. This is one of the reasons that it is desirable to havethe transporting wheel riding idly along the top of the form during thetamping operation of the machine, though another reason is thedesirability of maintaining this transporting wheel in such a positionthat a proper balancing of the machine upon the side form during thetamping operation will be facilitated.

When the occasion arises for transporting my machine along the top ofthe form, as indicated, it is merely necessary for the operator to lowerthe handle 60 to substantially longitudinal position and to lift therear end of the machine to the position shown in Figure 8. In thisposition, the entire weight of the front of` the machine is carried uponthe transporting wheel 63 which is riding upon the top of the form.However, it should be noted that the flanges of the roller I0 are stillin embracing relation to the top of the form. Thus, though the roller I0does not actually run upon the form in this position of adjustment, itdoes serve to guide the front end of the machine along the form andprevent the transporting roller and the front end of the machine fromrunning off the form.

It should also be noted that, in the position of adjustment shown inFigure 8, the set screw 14 bears upon the bed plate of the machine andnally transmits the weight from the U-shaped member 65 to the body ofthe machine. It should also be noted that, due to the adjustability ofthe set screw 14, the height to which the handle 60 must be lifted tobring about contact of this set screw 14 with the bed plate and totherefore transfer the weight of the machine to the transporting wheelmay be varied. This adjustment is useful in accommodating the height ofthese handles to the height of the operator, since it is apparent that ashort man may more readily transport the machine with the handle 60 at alower height than would be the case if the operator were a tall man.

In the removal of the machine from the side form, it is merely necessaryfor the operator to press down on the outer end of the handle 60 to liftthe forward end of the machine to such a position that the lower end ofpin 15 will occupy a position upon the upper edge of the side form A,similar to the position shown in Figure 6. The forward end of themachine is then swung laterally until the pin occupies a position at theopposite side of the side form. This causes the transporting wheel @3 tobe moved laterally olif the side form. The weight of the transportingwheel will then cause it to fall downwardly to a position where themember 65 will be moved beneath the keeper l2. In this position, thelifting of the handle 6i! will cause this keeper 12 to abut the U-shapedmember 55 and form a rigid contact so that the machine may then berolled away from the side form like a wheel barrow.

It will be seen from this that I have provided an extremely simple typeof tamping machine wherein all of the parts are balanced in such a waythat the machine may travel along the top of a side form without dangerof overturning. In the rst place, the traction rollers with their wideflanges eifectually guide the machine and the ability to position thetransporting wheel on the top of the side form with its weight supportedthereon in line with the center of gravity of the machine minimizes thedanger oi tilting. This danger is further decreased by the use oftamping members operating in converging planes.

It will also be apparent that the oiling mechanism which I have providedpermits of the. provision of an oil delivery pipe of suiicient size topractically eliminate all danger of clogging of the delivery port or ofthe pipe due to foreign matter which may accidentally get into thesepipes. On the other hand, the use of the exhaust gases for vaporizingthe oil insures that the particles of oil applied will be suiiicientlysmall and suiliciently spread out to produce ample lubrication,especially in view of the fact that these gases effect the applicationof the oil to the form under pressure and heat the oil, causing it tobecome thin and to readily vaporize.

It will likewise be obvious that the feature of my machine which permitsthe placing of the front end of the machine on the top of the side formin such a manner as to relieve the transporting wheel from vdownwardpressure greatly facilitates the movement of this transporting Wheelfrom its position along side the side form to the top of the side form,since the release of the U-shaped member 65 from the keeper l2 wouldotherwise be extremely diicult.

Various other features of importance have been previously explainedduring the description of this apparatus.

Having thus described my invention, what I claim is:

l. A machine for tamping earth along and under a concrete side formcomprising a carriage designed to ride upon said side form, a tampingunit, and means for oiling said side form embodying a means forvaporizing the oil.

2. A machine for tamping earth along and under a concrete side formcomprising a carriage designed to ride upon said side form, a tampingunit, and means for oiling said side form embodying ameans forintermingling the oil with hot gases and using the hot gases as avehicle for applying the oil to the side form.

3. A machine for tamping earth along and under a concrete side formcomprising a carriage, a tamping unit, a iiuid operated engine fordriving said tamping unit, a source of oil supply, and means forconducting the exhaust gases from said engine into contact with oil fromsaid source of oil vsupply and thence into contact with said side forms.

4. A machine for tamping earth along and under a concrete side formcomprising a carriage, a tamping unit, a iiuid operated engine fordriving said tamping unit, a source of oil supply, means for deliveringthe exhaust gases from said engine into contact with said side forms,and means for conducting oil from said source of oil supply into thepath of such exhaust gases during their travel towards said side form.

5. A machine for tamping earth along and under a concrete side formcomprising a carriage, a tamping unit, a uid operated engine for drivingsaid tamping unit, a source of oil supply, means for delivering theexhaust gases from said engine into contact with said side forms, and apipe leading from said source of oil supply and having a deliveryopening in the path of said exhaust gases.

6. A machine. for tamping earth along and under a concrete side formcomprising a carriage,

Lil

a tamping unit,l means for vdelivering oil to the side form comprising asource of oil supply, means for subjecting the oil to hot gases prior toapplication thereof 'to said side form, said hot gases being adapted tothin and vaporize said oil.

'7. A machine for delivering oil to a side form comprising a source ofoil supply, and means for conveying the oil to said side form by meansof a current of hot gases.

8. A machine for tamping earth along and under a concrete side formcomprising a carriage, a tamping unit, a transporting Wheel, means foradjusting said transporting wheel, and means for adjustably limiting theuppermost position of said wheel.

9. A machine for tamping earth along a concrete side form comprising acarriage, fianged rollers for embracing the top of said side form and atransporting wheel adapted to ride on the top of said side form, theflanges of one of said rollers being of such depth that the roller maybe lifted from said side form to transfer the weight of the machine tosaid transporting wheel while still retaining such iianges in a positionto prevent lateral displacement of the machine.

10. A machine for tamping earth along a concrete side form comprising acarriage, vertically adjustable flanged rollers for embracing the top ofsaid side form, and an adjustable transporting wheel normally adapted toride on the top of said side form, the flanges of one of said rollersbeing of such depth that the roller may be lifted from said side form totransfer the weight of the machine to said transporting Wheel whilestill retaining such anges in a position to prevent displacement of themachine.

1l. A machine for tamping earth along and under a concrete side formcomprising a carriage, a tamping unit, a transporting Wheel, means foradjusting said transporting Wheel, and a member on said carriageadjustable to a position with relation to said side form lto support theweight of the machine and to relieve said transporting Wheel of theWeight of said machine.

12. A machine for tamping earth along a concrete side form comprising acarriage, a transporting wheel movable into and out of operativeposition, a traction means for effecting movement of said carriage alongsaid side form, a member on one end of said carriage adapted to bepositioned on said side form to support the weight of said machine,means for delivering oil to both sides of said side form, and a handlestructure connected to said carriage and movable to one position fortransportation of said machine and to another position for guiding andbalancing said machine on said side form,

13. A machine for tamping earth along and under a side form comprising acarriage, a tamping unit, a transporting wheel normally adapted to rideon said side form in inoperative position, said transporting wheel andsaid carriage being adjustable relative to each other so that the Weightof the machine may be shifted to said transporting wheel on said sideform, and means for preventing lateral displacement of said carriagewhen said transporting Wheel is in inoperative position or when itsupports the Weight of said machine.

14. A machine for tamping earth along and under a side form comprising acarriage, a tamping unit, a transporting Wheel normally adapted to rideon said side form in inoperative position, said transporting wheel andsaid carriage being adjustable relative to each other, means forlimiting the uppermost position of said transporting Wheel so that itwill support the weight of said machine on said side form, and means forpreventing lateral displacement of said carriage When said transportingWheel is in inoperative position or when it supports the weight of saidmachine.

15. A tamping machine comprising a self-propelled carriage constructedto alone travel and alone maintain its balance upon a single side form,driven tamping means on said carriage for continuously tamping earthalong and under the side form While the carriage continuously advancesalong said side form, and means for oiling said side form and embodyinga means for intermingling the oil with hot gases and using the hot gasesas a vehicle for applying the oil to the side form.

16. A machine for tamping comprising a carriage constructed to ridedirectly upon and along a member under which material is'to be tamped, atamping means automatically operated to strike successive tamping blowsas said carriage travels along and upon said member, and means foroiling said member as the cai'- riage travels therealong and embodying ameans for intermingling the oil with hot gases and using the hot gasesas a vehicle for applying the oil to said member.

17. A machine for tamping comprising a carriage constructed to ridedirectly upon and along a member under which material is to be tamped,

a tamping means automatically operated to strike successive tampingblows as said carriage travels along and upon said member, atransporting wheel normally adapted to ride on said member ininoperative position as the carriage moves therealong, said transportingwheel and said carriage being adjustable relative to each other so thatthe weight of the machine may be shifted to said transporting wheel onsaid side form and means for preventing lateral displacement of saidcarriage when said transporting Wheel is in inoperative position or whenit supports the Weight of said machine. ,l

18. A machine for tamping comprising a carriage constructed to ridedirectly upon and along a member under which material is to be tamped, atamping means automatically operated to strike successive tamping blowsas said carriage travels along and uponsaid member, traction meansoperating upon the member along which said carriage rides to propel saidcarriage along said member during the tamping operation, said tractionmeans embodying positively driven flanged rollers adapted to operate onsaid member, a transporting Wheel independent of said traction membersand normally adapted to ride on said member in inoperative position asthe machine moves therealong, said transporting Wheel and said carriagebeing adjustable relative to each other, means for limiting theuppermost position of said transporting wheel so that it Will supportthe weight of said machine on said member, the forward flanged rollerbeing of such a type that even when the transporting Wheel is in itsuppermost position it will still cooperate with said member to guidesaid carriage there along.

JOSEPH EGGERT.

CERTIFICATE OF CORRECTION.

Patent No. 2,051,695. February 25, 1936.

JOSEPH EGGERT.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 3,second column, line 52, strike out the words "inwardly along theinclined edge" and insert instead supports the weight of the front end;and that the said Letters Patent should be read with this correctiontherein that the same may'oonform to the record of the case in thePatent Office.

Signed and sealed this 14th day of April, A. D. 1936.

(Seal) Acting Commissioner of Patents.

